1. Field of the Disclosure
The disclosed feature relates to a head mounted display device, in which an image display unit is attached to a frame having a front part to be positioned before eyes of an user and a temple part mountable on the user's ear, connected with a side edge portion of the front part. In particular, the disclosed feature relates to the head mounted display device, in which the image display unit is detachably attached to a front edge portion of the temple part.
2. Description of the Related Art
Various head mounted display devices (hereafter HMD) have been commercialized as portable displays for TV games and personal digital assistances. For example, in Japanese Unexamined Patent Application Publication No. 2007-148131 (hereafter JP 2007-148131), an eyeglass type HMD is disclosed as an example of HMD. In the eyeglass type HMD, an image display unit is disposed in front of a frame of the eyeglass type HMD such that the image display unit is adjustable in a right-and-left direction. Particularly, an adopter member, in which a permanent magnet is embedded, is detachably disposed in the upper edges of both a left rim and a right rim that support lens of the eyeglass type HMD. A rail is fixed to the adopter member by the permanent magnet, and a retaining shaft is movably disposed in the rail. The image display unit is fixed to the frame via a holding ring. The holding ring surrounds the image display unit and is fixed to the retaining shaft by a screw nut.
In U.S. Pat. No. 6,204,974 (hereafter U.S. Pat. No. 6,204,974), another eyeglass type HMD is disclosed. In the eyeglass type HMD, a housing assembly for housing an image display unit is retained in a temple of a frame of the eyeglass type HMD by a clamp assembly that includes a mounting fixture and a clamp. In detail, a pair of pins extend from the mounting fixture that is retained in the housing assembly. The pair of pins penetrate the temple from the outside of the temple, and the housing assembly is retained in the temple at a rearward position apart from a connection part connecting the temple and a front supporting eyeglass lenses.
In U.S. Pat. No. 4,869,575 (hereafter U.S. Pat. No. 4,869,575), there is disclosed an eyeglass type HMD similar to the eyeglass type HMD disclosed in U.S. Pat. No. 6,204,974. In the eyeglass type HMD, an eyeglass frame has a front supporting eyeglass lenses, a pair of connection parts fixed in both sides of the front, and a pair of temples rotatably mounted on both connection parts. A clip type mounting means has an arm and is detachably attached to one of the temples. A display unit having a screen is mounted on a front edge portion of the arm.